//var let const

const fs = require('fs')

fs.readFile('./files/1.txt','utf8',(err,data)=> {
    if(err) return console.log(err)
    console.log(data)
})

 fs.readFile('./files/1.txt',(err,data)=> {
    if(err) return console.log(err)
    console.log(data.toString()) // 不写'utf8', 加上toString()
}) 